Method of and apparatus for cleaning and pickling metal



Nov. 19, 1940. T; E. NICKLAS 2,221,811

METHODOF AND APPARATUS FOR CLEANING AND PICKLING METAL Filed Feb. 16,1958 INVENTOR.

BY mwgg ATTORNEYfi @aientefi New. 3%, 394% ING PIS 5.1

G JKETAL Thomas E. Nicklas, Bay Village, Ohio Application February 16,1938, Serial No. 190,7831.

6 Claims.

The present invention relates to a novel method and apparatus forpickling metal in the form of a. strip, wire or the like. It isgenerally the purpose of a pickling operation to subject the surface ofa metal to the solvent action of a chemical solution whereby oxides,dirt, sand, and other foreign substances are removed in order to renderthe surface of the metal in a physically and chemically clean condition.Such a pickling 10' operation, accordingly, comprises in eifect combinedwashing and chemical actions. Bubbles of hydrogen gas are usuallyliberated as a result of the chemical action, and tend to adhere to themetal surface, thus impeding further chemical 1'5 section as well asproducing an uneven pickling eifect, and in the case of steel, anembrittlement of the ,metal due to the action of nascent hydrogen, X

The general object and nature of my invention, therefore, and in orderto enhance and improve the metal pickling operation, is to provide amethod and apparatus for rapidly moving the metal in strip or wire formthrough the pickling bath so that the gaseous products of chemicalreaction are immediately and promptly removed from the surface of themetal immediately upon formation, and the washing and cleaning action ofthe pickling bath upon the metal is greatly increased. Briefly outlined,my invention provides a means and method for coiling and uncoiling metalin strip, wire, or like form, and by means of a power drive, so that itis caused to be drawn through the pickling bath in straight line orlinear form.

To theaccomplishment of the foregoing and related ends, said invention,then, consists of the means hereinafter fully described and particularlypointed out in the claims, the annexed drawing and the followingdescription setting forth in detail certain means and one mode ofcarrying out the invention, such disclosed means and mode illustrating,however, but one of various ways in which the principle of the inventionmay be used. I

In said annexed drawing: 7

Fig. 1 is an elevational view in section, illustrating an apparatusembodying the principle of my invention; and Fig. 2 is a top plan viewof Fig. 1.

50 Now refen'ing more particularly to the drawing, there is showntherein a pickling bath tank housing I having the lining of an acid,alkali, or corrosion resistance material 2. A pair of vertical shafts 3extend through the bottom of the z tank I and are sealed with respectthereto by means of the stumng boxes or packing glands d. The shafts 3are journalled in the thrust bearings 5 and 8 carried by the supportinghousings i. The lower ends of the shafts igare in turn again sealed withrespect to the housings i .by means of the packing glands d." Beveliedgears 8 and I9 connect the lower end of the shafts 3 to the reversibleelectric drive motors l l.

The upper ends I2 of the shafts 3 are in the form of fiat or squaredends whereby they make a separable driving connection with suitable re=cesses in the bottoms of the drums G3. The drums I3 have a spindleportion i i adapted to receive the metal to be pickled in strip or wireform, such as the coil of metal strip Id. The ends of the metal strip I5are removably connected to the spindles Id in any suitable manner, suchas by means of a hooked or rebent end I'I passing through the axiallyextending slot It.

Eye bolts I? project from the end of the spindles I4 and .re adapted tobe engaged by the hooks I9 car.-ed by the lifting plate 20.

The operation of the above described apparatus is as followsThe drums I3with their spindles I4 are initially removed from the pickling tank Iand the coil of metal, strip I5 is then placed upon one of the spindlesand its free end connected to the other, substantially as indicated inFig. 2. The drums I3 are then lowered by means of the lifting plate intothe pickling tank I whereupon they enter into driving connection withthe upper ends of the shafts 3. The hooks I9 are then disengaged fromthe eye bolts I8 and the drums I3 rotated by means of the drive motors II so as to wind the coil I5 from one drum to the other. The drums arerotated at such a speed as to obtain a linear velocity of the strip I5through the pickling bath sufficient to accomplish the clearing of thehydrogen bubbles and prevent any surface accumulations. Suitable speedsfor the purpose may be from 10 to 100 feet per minute, but obviously theinvention is not limited tospecific speeds. This last operation may berepeated or reversed by reversing of the drive motors and recoiling thestrip I5 back upon the drum upon which it was originally placed. Thestrength of the pickling solution, the nature of the particular metal tobe pickled, and the degree of pickling desired will determine the numberof times that the metal strip I 5 is to be passed through the picklingsolution, or coiled and recoiled, on the respective drums. As soon asbubbles of gas such as hydrogenare formed upon the surface of the strip,the linear velocity of the latter together with the frictionalresistance of its passage through the solution will be sufiicient toimmediately dislodge and remove such gas bubbles. The frictionfiuidresistance upon the surface of the metal strip also aids in themechanically washing and cleaning action of the solution.

It is apparent from the drawing that the outside portion of the coil,where the radius is relatively large, starts on the empty oppositespindle M of much smaller diameter. In other words the part of the coilwhich is towards the outside and hence curved on a large radius on onespindle is more sharply curved when transferred to the other, while theformer inner part of the coil is wound on a larger radius. The radius ofbend applied to the metal in the middle of the coil does not change muchby this treatment, but none of the coil escapes a bend on a radius ofsubstantially half the outside radius, and every portion of the coil(except the holding tags) is successively straightened and rebent in thebath. The change of curvature so caused will obviously tend to crack offflakes of scale which have been loosened by the pickling bath.

A strong local washing action to carry loosened scale away occurs at theline of tangency where the straight portion of the strip is coming onthe coil, along which line (shown as point A in Fig. 2) the liquid issqueezed out by the pinching action between face B and face C.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the means andthe steps herein disclosed, provided those stated by any of thefollowing claims or their equivalent be employed.

I therefore particularly point out and distinctly claim as myinvention---- 1. A method of cleaning and pickling metal in coiled formcomprising the steps of immersing such coil in a pickling bath,uncoiling and then recoiling it while immersed therein and at a linearvelocity sufficient to dislodge gaseous particles forming on the surfacethereof.

2'. A method of cleaning and pickling metal in coiled form comprisingthe steps of immersing such coil in a pickling bath, uncoiling and thenrecoiling it while immersed therein and at a linear velocity sufficientto dislodge gaseous particles forming on the surface thereof, andrepeating such uncoiling and recoiling operation until the picklingaction is complete.

3. In an apparatus for cleaning and pickling metal, the combination of apickling bath container, rotatable means in said container for coilingand uncoiling a coil of metal, power driving means located exteriorly ofsaid container and a driving connection between said power means andsaid rotatable means.

4. In an apparatus for cleaning and pickling metal, the combination of apickling bath container, a pair of rotatable drums so arranged in saidcontainer as to receive a coil of metal mounted on one of said drums andconnected for recoiling on the other of said drums, power driving meanslocated exteriorly of said container,

and drive shafts connecting said drums to said power driving means.

5. In an apparatus for cleaning and pickling metal, the combination of apickling bath container, a pair of rotatable drums so arranged in saidcontainer as to receive a coil of metal mounted on one of said drums andconnected for recoiling on the other of said drums, power driving meanslocated exteriorly of said container, drive shafts connecting said drumsto said power driving means, and a separable connection between saidshafts and said drums.

6. In an apparatus for cleaning and pickling metal, the combination of apickling bath container, rotatable means in said container for coilingand uncoiling a coil of metal, and power driving means for saidrotatable means.

THOMAS E. NICKLAS.

